Search results for "Method"
showing 10 items of 13253 documents
DISTRIBUTION OF CARBON STARS IN THE GALAXY
2018
A search for new faint carbon (C) stars in the Polar region δ > 55o has been accomplished by obtaining objective prism spectra in the near infrared 550 -- 900 nm on images of CCD camera of Baldone Schmidt telescope of Astrophysical observatory. The positions of stars having color indices (J – K) > 1.3 mag in Two Micron All Sky Infrared Survey (2MASS) were selected to pick out suspicious carbon stars.Our survey is limited in brightness by J < 10 mag. 24 new carbon stars were found and their characteristics obtained. The correlative relation between Teff and spectral gradient [757 – 685] was confirmed. Such characteristics as Teff, distance from the Sun, absolute Mk were obtained…
A kinetic-catalytic method for iodide based on the simultaneous addition of inhibitor and substrate
1987
Abstract A kinetic-catalytic method of analysis, based on the addition of a mixture of inhibitor and substrate, at a constant rate, over the catalyst in the presence of the other component of the indicator reaction is studied. The method is applied to the determination of iodide using the Ce(IV)As(III) catalytic reaction and Hg(II) as inhibitor. Under suitable experimental conditions the absorbance of the unconsumed Ce(IV) is inversely proportional to the initial iodide concentration.
Acoustic characterization of Silica aerogel clamped plates for perfect absorption purpose
2017
International audience; Silica aerogel has been widely studied as bulk material for its extremely low density and thermal conductivity. Plates or membranes made of this extremely soft materials exhibits interesting properties for sound absorption. A novel signal processing method for the characterization of an acoustic metamaterial made of silica aerogel clamped plates is presented. The acoustic impedance of a silica aerogel clamped plate is derived from the elastic theory for the flexural waves, while the transfer matrix method is used to model reflection and transmission coefficients of a single plate. Experimental results are obtained by using an acoustic impedance tube. The difference b…
Theoretical Study of the Electronic Excited States of Tetracyanoethylene and Its Radical Anion
2005
The low-lying electronic states of tetracyanoethylene (TCNE) and its radical anion were studied using multiconfigurational second-order perturbation theory (CASPT2) and extended atomic natural orbital (ANO) basis sets. The results obtained yield a full interpretation of the electronic absorption spectra, explain the spectral changes undergone upon reduction, give support to the occurrence of a bound excited state for the anionic species, and provide valuable information for the rationalization of the experimental data obtained with electron transmission spectroscopy.
Probing NiO nanocrystals by EXAFS spectroscopy
2010
Abstract The structure relaxation in nanocrystalline NiO (nano-NiO, 13 nm crystallite size) has been studied by X-ray absorption spectroscopy at the Ni K-edge at 300 K. Conventional single-scattering analysis of the EXAFS signals from the first two coordination shells showed a lattice volume expansion by about 1% and a contraction of the Ni–O bonds by about 0.5% in nano-NiO compared to microcrystalline NiO. A more sophisticated approach, based on a combination of classical molecular dynamics and ab initio multiple-scattering EXAFS theory, allowed us to interpret both static relaxation and lattice dynamics in nano-NiO.
On the Low-Lying Excited States ofsym-Triazine-Based Herbicides
2005
We report a joint computational and luminescence study on the low-lying excited states of sym-triazines, namely, 1,3,5-triazine (1) and the ubiquitous herbicides atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (2)] and ametryn [6-methylthio-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine (3)]. Geometrical structures, energetics, and transition and state properties of I and 2 were computed at the TD-DFT, CASSCF, and CASPT2 levels of theory. The fluorescence and phosphorescence emission spectra, lifetimes, and fluorescence quantum yields were measured for the three compounds, and from these, the energies of the lowest excited states and their corresponding radiative rates…
A call for dissensus in art education!
2019
This article argues for the relevance of the term dissensus by the French philosopher Jacques Rancière in an art educational context in particular and an educational context in general. This argument is based on research referred to in this article, where the author made use of dissensus to analyse how encounters with contemporary art contribute to movements in youngsters’ ways of relating to artworks and the environment that surrounds them, as well as changes in the ways of relating to themselves and others ‐ what here is called events of subjectivation. As dissensus is seen as a premise for subjectivation, the author argues for initiating dissensus by introducing students to both art and …
De Kelsen a la informática jurídica: una entrevista con Mario G. Losano
2018
Desde que su mentor, Norberto Bobbio, le encargara la traducción de la segunda edición de la Teoría pura del derecho (1960), la carrera de Mario G. Losano ha sido tan larga como polifacética. En esta entrevista, conversamos sobre su formación y sobre el contexto cultural que envolvió el inicio de su carrera académica en Italia. Posteriormente, nos centramos en dos de los principales temas de su producción académica. Por un lado, profundizamos en sus estudios kelsenianos, destacando el enfoque histórico que caracteriza su aproximación a los problemas iusfilosóficos. Y, por otro lado, abordamos el asunto de los orígenes y el desarrollo de la informática jurídica, de la cual el profesor Losano…
Promoting children’s participation: the role of teachers in preschool and primary school learning sessions
2010
The aim of this study is to provide insights into the social construction of participation in joint activities in Finnish preschool and primary school classrooms. The article deals with two issues: How do teachers promote participation in a preschool classroom as compared with a primary school classroom? What similarities and differences are found? It also considers the question of how the similarities contribute to the continuity from preschool to primary school in terms of participation. Based on observation data insights are provided into the interactions between teachers and children by using extracts from teacher‐led learning sessions. The teachers used a diversity of strategies to pro…
Tutorial Action in Small Groups: An Educational Experience With University Students
2016
Resumen:En el presente estudio se plantean tres objetivos. El primero, describir las principales características de un programa de acción tutorial desarrollado en una asignatura de una facultad de formación de profesorado. El segundo, determinar la valoración del grado de importancia que el estudiantado otorga a un grupo de competencias transversales y el grado de conocimiento sobre aspectos relacionados con la metodología de investigación durante el proceso de acción tutorial. El tercero, discutir el papel que juega la acción tutorial en la formación universitaria dentro del nuevo espacio europeo de educación superior. La experiencia se desarrolló en el curso académico 2014-2015. Participa…